1. Field of the Invention
This is a continuation of application Ser. No. 688,306, filed Jan. 2, 1985, now abandoned.
This invention relates to a reading-in circuit for cameras equipped with means for reading photographic information codes recorded on the film cartridge or on the film surface.
2. Description of the Prior Art
In the art of cameras, it is known that photographic information such as film sensitivity, frame number and exposure range, recorded on the film cartridge or the film leader are read out and automatically set in the computation control curcuit as computation control information.
Of the cameras having automatic setting means of this kind, among others, one camera uses film cartridges having electrical contacts as the photographic information code when loaded to perform automatic setting of the aforesaid photographic information, if the code is read in when the back cover is not yet closed, since the contacts as unstable, erroneous reading are very possible.
To improve this, a method employed for initiating reading may be considered in which a switch detects when the back cover is fully closed after the film cartridge is loaded. Even in this case, due to vibrations occurring when the back cover is closed, just after the back cover is closed the contacts will become unstable, also producing some possibility of erroneous reading. On the other hand, with the film loaded, after a prescribed time from the closure of the back cover has passed, the contacts are established, assuming a condition suitable for code reading. Also, even if the information is read out when the contacts are stabilized, then, upon lapse of a subsequent long time, the interface between the contact and the information code area will produce erroneous electrical conductivity since dust build up and rust eats into the confronting surfaces. Therefore, even though accurate information readings were once attained, if the reading operation continues, erroneous information reading will possibly later accidentally occur.
An object of the present invention is to provide a read-in device in which after the film has been loaded in the camera and the back cover has been closed, when a prescribed time lapses, photographic information provided on film container or the film are read in, whereby it is possible to always carry out information reading with the contacts stabilized.
Another object of the invention is to provide a read-in device which has overcome the above-described drawbacks by reading in photographic information only for a prescribed time after the film has been loaded in the camera and after the back cover has been closed.
Other objects of the invention will become apparent from the following description of an embodiment thereof by reference to the accompanying drawings.